Twenty people allegedly involved in the organization were arrested Tuesday in Chicago, four in Cincinnati and one in Laredo, Texas, prosecutors said. Thirteen people were already in custody or are fugitives.
The group allegedly imported drugs to the Chicago area and acted as both a retailer and wholesaler, investigators said.
The investigation, which began in March 2010, was carried out by the U.S. Drug Enforcement Administration and Chicago police. Investigators said they have seized more than 30 pounds of heroin, 15 pounds of cocaine and $1 million in cash.